Commentary: The Supreme Court went out of its way to ignore common sense on bump stocks

On Friday, the Supreme Court once more narrowed the power of the government to protect the American people from gun violence. In a 6-3 decision, split along ideological lines, the justices invalidated a rule adopted by the Bureau of Alcohol, Tobacco, Firearms and Explosives that prohibited a device, bump stocks, that effectively turns semiautomatic rifles into machine guns. Although the case involved the interpretation of a federal law and not the 2nd Amendment, it again shows us that the conservative majority on the court will protect gun rights and put lives in needless jeopardy.

A federal statute adopted in 1934 prohibits people from having machine guns. Congress passed the law because machine guns have the capacity to fire many bullets quickly and thus cause enormous harm. The law defines a machine gun as one that automatically fires “more than one shot, without manual reloading, by a single function of the trigger.” By contrast, with a semiautomatic firearm, the shooter must release and re-engage the trigger to fire multiple shots.

A bump stock, however, allows a semiautomatic gun to repeatedly fire, at nearly the rate of a machine gun. A rifle equipped with a bump stock can fire at a rate of between 400 and 800 rounds per minute.

In 2017, a gunman in Las Vegas fired into a crowd at a music festival, killing 58 people and wounding more than 500 others. The gunman’s weapons had bump stocks.

The tragedy in Las Vegas caused the ATF to change its position and deem bump stocks to be prohibited by the statute that outlaws machine guns. It is worth noting that the new rule was adopted by the conservative Trump administration and even the National Rifle Association agreed regulation was necessary. The rule ordered owners of bump stocks to destroy them or surrender them within 90 days.

The new ATF rule made enormous sense. A weapon outfitted with a bump stock is for all intents and purposes a machine gun; common sense dictates that it should fall under the federal ban. As Justice Sonia Sotomayor wrote in her dissent on Friday, “When I see a bird that walks like a duck, swims like a duck, and quacks like a duck, I call that bird a duck.”

Unfortunately, the court, in a majority opinion written by Justice Clarence Thomas, decided minute differences in bump stock weapons and machine guns mean the ATF lacked the authority to adopt its rule. A “semiautomatic rifle equipped with a bump stock does not fire more than one shot by a single function of the trigger,” he wrote. “All that a bump stock does is accelerate the rate of fire by causing these distinct function(s) of the trigger to occur in rapid succession.”

In addition to discounting common sense, the court ignored the principle that there should be deference to federal agencies, such as the ATF, when they interpret federal statutes. It also failed to follow the principle that statutes should be interpreted to fulfill their purpose.

Both Thomas’ majority opinion and Sotomayor’s dissent include detailed descriptions of how bump stocks work. Both agree, and it is unassailable, that bump stocks allow a semiautomatic weapon to perform as a machine gun though the mechanics are slightly – very slightly – different. And it also is undeniable that such weapons can kill a large number of people in a short amount of time.

Why in the world would six Supreme Court justices deny the federal government the ability to interpret the federal law to prohibit bump stocks? The only explanation is that the ultraconservative majority supports gun rights virtually without question. They just as steadfastly refuse to recognize the enormous toll of gun violence in the United States.

Because this case does not involve the Second Amendment, Congress could adopt a law prohibiting bump stocks. The gun lobby has so far prevented this from happening. We have to hope it will not take another Las Vegas-type tragedy for Congress to outlaw a device that serves no purpose except to effectively convert a rifle into a machine gun.

Erwin Chemerinsky is dean of the UC Berkeley School of Law.